Trigger swing protract-retract mechanism for ball point pens having different colored ink reservoirs

ABSTRACT

A TRIGGER SWING PROTRACT-RETRACT MECHANISM FOR BALL POINT PENS WHICH HAVE SEVERAL DIFFERENT COLORED FLUID INK RESERVOIRS, WHEREIN A SPRING STIRRUP RING IS PROVIDED WITH AN INTERNAL CAM SURFACE FOR ENGAGEMENT WITH THE CURVED LONGITUDINAL NOTCH OF THE TRIGGER BODY. IN A PREFERRED EMBODIMENT, THE RING IS OPEN AND THE INTERNAL CAM SURFACE LIES OPPOSITE THE OPEN ARMS OF THE RING AT AN END   OF THE TRIGGER SO THAT THE RING POSITIVELY ENGAGES THE NOTCH TO RESIST DISPLACEMENT WHILE PERMITTING THE TRIGGER TO BE FREELY MOVED TO VARIOUS POSITIONS FOR SELECTING ONE OF THE DIFFERENT COLORED RESERVOIRS.

Jan. 5, 1971 K. H. HEINZ 3,552,867

TRIGGER SWING PROTRACT-RETRACT MECHANISM FOR BALL POINT PENS HAVING DIFFERENT COLORED INK RESERVOIRS Filed July 24, 1968 KARL HEINRICH HEINZ BY Aha/km A). f

ATTORNEY United States Patent 3,552,867 TRIGGER SWING PROTRACT-RETRACT MECHA- NISM FOR BALL POINT 'PENS HAVING DIF- FERENT COLORED INK RESERVOIRS Karl Heinrich Heinz, 13 Finkemstrasse, 8280 Kreuzlingen, Switzerland Filed July 24, 1968, Ser. No. 747,159 Claims priority, application Germany, July 24, 1967, 1,561,834 Int. Cl. B43k 5/16, 24/06 U.S. Cl. 401-110 1 Claim ABSTRACT OF THE DISCLOSURE A trigger swing protract-retract mechanism for ball point pens which have several different colored fluid ink reservoirs, wherein a spring stirrup ring is provided with an internal cam surface for engagement with the curved longitudinal notch of the trigger body. In a preferred embodiment, the ring is open and the internal cam surface lies opposite the open arms of the ring at an end of the trigger so that the ring positively engages the notch to resist displacement while permitting the trigger to be freely moved to various positions for selecting one of the different colored reservoirs.

This invention relates to a trigger swing protract-retract mechanism for ball point pens which have several different colored fluid reservoirs. The trigger swing element acts on one of the several differently colored fluid reservoirs which are provided. A locking body in the shape of a pendulum assists in securing the selected writing fluid reservoir in the positions of rest and use. The pendulum is positively linked into the trigger thrust element and is adapted to roll freely transverse to the direction of push.

An essential disadvantage of ball pens of this type lies in the fact that the ball is adapted to fall and roll; freely, partly in the control track of the trigger or thrust member and partly in the transverse groove in the other part of the pen and thus can in no way be engaged on the pressure movement in any position of use particularly, if the circular notching is slanted or lies underneath. Due to gravity the ball whose inertia has been lifted remains in its initial position or even rolls backward, so that the pressure movement has often to be repeated.

In order to overcome this difl'lculty in the prior art, lubricating grease was applied to the bedding of the circular notched guide and roller bearing, but this proved unsatisfactory because the benefit lasts only for so long as the holding capacity of the layer of grease is retained.

One object of the present invention is to eliminate or alleviate these disadvantages. This is made possible with relatively low production cost in that a ring washer, preferably an open spring stirrup-washer is provided whose inwardly projecting engagement cam engages in the sunken semi-circular longitudinally notched guide of the trigger or thrust element and in that this spring stirrup-washer is mounted loosely within a transverse groove provided in the trigger side part of the ball pen to adapt the trigger for rotary movement so that there is play on all sides. Due to the engagement of the cam of the spring stirrup washer with the longitudinal notch of the trigger element, the washer always lies transversely to the direction of forward push and is not afiected by the gravity to prevent its proper function. The inertia of the protract-retract mechanism remains constant in any position of the triggers, so that, when pushed forward, repeated pressure is unnecessary to disengage the trigger.

A further simplification lies in that thespring stirrupwasher is coupled to the trigger element of the ball pen in such a way that the tensioned arms of the open spring stirrup-washer force the cam into light engagement with the sunkeninclined notch on the end of the trigger element.

The protract-retract mechanism is used for ball point pens having several reservoirs, each with differently coloured inks and each with swing selection by means of the trigger element provided with a curved notched guide and swing bearing mounted in a screw head sleeve.

The subject matter of the invention is shown by way of example, in the preferred embodiment, shown in the drawing of which:

FIG. 1 shows the trigger swing protract-retract mechanism for a ball point pen having different colored ink reservoirs;

FIG. 2 shows the top plan view of a spring stirrup ring with the internal cam surface which is a critical element of the combination and which, in this figure, is open;

FIG. 3 is a top plan view of a spring stirrup ring having an internal cam surface for engagement with the curved longitudinal notch of the trigger and which, in this modification, is closed; and

FIG. 4 is a perspective view of a modification of an open spring stirrup ring similar to FIG. 2 but in which the internal cam surface which engages the curved longitudinal notch of the trigger element is made by deforming the ring inwardly.

As shown in FIG. 1, the construction of the trigger swing protract-retraot mechanism for ball point pens having several different colored fluid reservoirs embodies the protract-retract trigger element 47 in novel association with the open or closed spring stirrup ring, as shown per se in FIGS. 2-4. The generally cylindrical trigger element 47 comprises a curved longitudinal notch 4 which has a semi-circular cross-section and a bearing portion 49 integral therewith and preferably formed in one piece therewith. The head sleeve 53 which is threaded on its outside for engaging the pen outer barrel (not shown) serves to mount the trigger element 47 with the bearing portion 49 projecting axially below the bottom rim 57 of the sleeve 53. The curved longitudinal notch 4 of the trigger cylindrical body portion 47' moves downwardly. The pendulum 52 is fitted with ball portion 58 which fits into bearing 49. The trigger body 47' moves up and down in the head sleeve 53. The head sleeve 53 is provided with an inner transverse groove 54 into which a spring stirrup ring 24, as shown in FIG. 2, or 25, as shown in FIG. 3, or 28 as shown in FIG. 4, is fitted. The curved notch 4 of the trigger element receives the radially inwardly projecting cam 26 or 27 of the spring stirrup ring. The arms 24 or 28 help to hold the ring in place at the base. A disc 56 may be engaged in the transverse groove 51 above bevel 50 and against the bottom rim 57 of the head sleeve 53.

FIG. 2 shows a spring stirrup ring 24 with internal cam surface 26 which has a thickened curved form such that it fits tightly into the groove 4 while the arms 24' opposite the cam surface 26 are relatively thin and serve to tension the cam 26 into tight position in the groove. This form of the ring is preferred over the form shown in FIG. 3 wherein the arms are closed, so to speak, to form a continuous ring 25 with cam surface 26.

Equally useful but more economical to manufacture is the spring stirrup ring 28 shown in FIG. 4 wherein the cam surface is not formed by thickening the portion of the ring opposite the arms but is rather formed by indentation at indented cam surface 27 opposite arms 28, the material and dimensions of this ring being such that excellent spring tension can be maintained.

3 It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art being possible, without departing from the scope thereof, as defined in the appendant claim.

What I claim is: 1. A trigger swing protract-retract mechanism for a ball point pen having differently colored fluid reservoirs which is mounted in a sleeve (53), threaded on its outside to engage the outer barrel of the pen, said mechanism comprising:

(a) an elongated, generally cylindrical trigger element (47) which is axially mounted in said sleeve;

(b) said trigger element having a curved longitudinal notch (4), a bevel (50) near the bottom enda transverse groove (51) above said bevel and a bearing portion (49) below said groove at the bottom end thereof, the notch, bearing portion, bevel and transverse groove all being integral with the generally cylindrical body of said trigger element;

(c) said bearing portion projecting axially below the bottom rim (57) of said sleeve;

(d) a pendulum (52) having a ball extension (58) which fits into said bearing portion (49);

(e) said sleeve (53) being provided with an inner groove (54) at its base; and,

(f) a spring stirrup ring (24) having an internal Ea-m surface for engagement with said curved longitudinal notch of said trigger element and having open arms opposite said cam surface, said ring fitting into said inner groove (54) to permit free rotation of said trigger element with the trigger in retracted position and tight engagement of said trigger element with the trigger in protracted position and with the pendulum (52) in the position for the selected reservoir there by preventing undesired release of the ink mechanism after the color has been selected through rotation and protraction of the trigger mechanism.

References Cited UNITED STATES PATENTS 3,262,426 7/1966 Bross II 40133 2,610,611 9/1952 Martin 401110 FOREIGN PATENTS 1,128,363 8/1956 France -1 401--l10 1,228,964 11/1966 Germany 401-110 1,259,734 5/1968 Germany 401110 LAWRENCE CHARLES, Primary Examiner 

